The present invention generally relates to a storage controller, and in particular relates to a storage controller that gives consideration to the performance or reliability of a physical volume upon adding a physical volume, which is allocated to a logical volume, to a logical volume.
As background art relating to this kind of storage controller, for instance, the storage control system described in Japanese Patent Laid-Open Publication No. 2004-13547 is known. This storage control system aims to improve the access performance to data and secure the reliability thereof in technology of allocating data to a data storage area of a plurality of storages, and has a computer, a plurality of storage apparatuses for storing data to be used by a program of the computer, and an allocation device for allocating data to a prescribed storage area for storing such data, wherein the allocation device decides the position of the storage area to be allocated based on characteristic information of the storage apparatus and volume requirement information showing the type or usage of data.
Further, Japanese Patent Laid-Open Publication No. 2003-15915 describes an automatic expansion method of capacity in a storage apparatus. With this method, the storage area of a storage apparatus is not decided uniquely, but is rather decided dynamically. The storage controller monitors the logical block address of the read or write I/O to be access from a host to a logical volume of the storage apparatus. The storage controller dynamically extends the storage area of the logical volume based on the acquired logical block address. Moreover, the storage controller reduces/expands the storage area of the logical volume based on the capacity reduction/expansion command of the logical volume from a command unit of the host to a volume server.